我正在尝试为新表单编写JUnit，并且已在此表单中使用ListGrid。但是，当我为此表单运行JUnit时，出现以下错误。我只能在运行JUnit时才遇到此问题，除了它可以完全正常工作之外。
java.lang.RuntimeException: Remote test failed at 10.120.15.15 / Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.19) Gecko/2010031422 Firefox/3.0.19
at com.google.gwt.junit.JUnitShell.processTestResult(JUnitShell.java:1288)
at com.google.gwt.junit.JUnitShell.runTestImpl(JUnitShell.java:1408)
at com.google.gwt.junit.JUnitShell.runTestImpl(JUnitShell.java:1309)
at com.google.gwt.junit.JUnitShell.runTest(JUnitShell.java:653)
at com.google.gwt.junit.client.GWTTestCase.runTest(GWTTestCase.java:441)
at junit.framework.TestCase.runBare(TestCase.java:134)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at com.google.gwt.junit.client.GWTTestCase.run(GWTTestCase.java:296)
at junit.framework.TestSuite.runTest(TestSuite.java:243)
at junit.framework.TestSuite.run(TestSuite.java:238)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: java.lang.Exception: java.lang.ExceptionInInitializerError
at com.verifone.isd.psc.config.client.pres.view.widgets.SMSListGrid.<init>(SMSListGrid.java:15)
at com.verifone.isd.psc.config.client.pres.view.widgets.FormElementType$29.buildWidget(FormElementType.java:219)
at com.verifone.isd.psc.config.client.pres.view.widgets.FormElementType$29.buildWidget(FormElementType.java:1)
at com.verifone.isd.psc.config.client.pres.view.widgets.SMSWidgetFactory.build(SMSWidgetFactory.java:74)
at com.verifone.isd.psc.config.client.pres.controller.TabBuilder.buildWidgets(TabBuilder.java:114)
at com.verifone.isd.psc.config.client.pres.controller.TabBuilder.process(TabBuilder.java:60)
at com.verifone.isd.psc.config.client.pres.common.ImplTestBase.buildTabs(ImplTestBase.java:201)
at com.verifone.isd.psc.config.client.pres.common.ImplTestBase.initialize(ImplTestBase.java:134)
at com.verifone.isd.psc.config.client.pres.common.ImplTestBase.gwtSetUp(ImplTestBase.java:66)
at com.google.gwt.junit.client.GWTTestCase.setUp(GWTTestCase.java:255)
at com.google.gwt.junit.client.GWTTestCase.runBare(GWTTestCase.java:187)
at com.google.gwt.junit.client.GWTTestCase.__doRunTest(GWTTestCase.java:129)
at com.google.gwt.junit.client.impl.GWTRunner.runTest(GWTRunner.java:389)
at com.google.gwt.junit.client.impl.GWTRunner.doRunTest(GWTRunner.java:318)
at com.google.gwt.junit.client.impl.GWTRunner.access$9(GWTRunner.java:312)
at com.google.gwt.junit.client.impl.GWTRunner$TestBlockListener.onSuccess(GWTRunner.java:107)
at com.google.gwt.junit.client.impl.GWTRunner$InitialResponseListener.onSuccess(GWTRunner.java:63)
at com.google.gwt.junit.client.impl.GWTRunner$InitialResponseListener.onSuccess(GWTRunner.java:1)
at com.google.gwt.user.client.rpc.impl.RequestCallbackAdapter.onResponseReceived(RequestCallbackAdapter.java:232)
at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:287)
at com.google.gwt.http.client.RequestBuilder$1.onReadyStateChange(RequestBuilder.java:395)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:337)
at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:218)
at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136)
at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561)
at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269)
at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:220)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:292)
at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:546)
at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:363)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.lang.Exception: com.google.gwt.core.client.JavaScriptException: (null): null
at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:248)
at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136)
at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561)
at com.google.gwt.dev.shell.ModuleSpace.invokeNativeVoid(ModuleSpace.java:289)
at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeVoid(JavaScriptHost.java:107)
at com.smartgwt.client.widgets.BaseWidget.init(BaseWidget.java)
at com.smartgwt.client.widgets.BaseWidget.<clinit>(BaseWidget.java:52)
... 47 more
请说明为什么无法创建ListGrid。
谢谢。